Description
Original Philips lower shaving unit 422203624371
The Philips Norelco 422203624371 lower shaving unit is the internal mechanical mechanism responsible for rotating the three shaving heads. It is the mechanical heart of the shaving head – without this unit, the blades will not rotate. This is an OEM original part, manufactured to Philips standards, and fits Series 9, Series 8, Series 7 and Series 6 machines.
Is your shaver making noise? Are the shaving heads spinning hard or unevenly? The most common cause is wear and tear on the internal rotation mechanism – the lower shaving unit. Check that your shaver model is listed below, and get back to a smooth, quiet shave.
What exactly does the lower shaving unit do – and why does it break?
The lower shaving unit is the drive interface between the machine’s motor and the three shaving heads. It translates the motor’s movement into uniform and precise rotation of each head individually. Over time, the rotation axis and internal gear mechanism wear out – the machine starts to make noise, the rotation becomes uneven, and the shaving sensation deteriorates. In our technicians’ experience, a continuous “grinding” noise from the head – as opposed to the noise from the handle – almost always indicates wear in the lower unit.
Signs that the lower unit requires replacement:
- ✅ Unusual noise from the head area – grinding, creaking, or repetitive clicking
- ✅ Shaving heads that rotate heavily or at an uneven rate
- ✅ A stronger than usual vibration sensation in the head area
- ✅ Less close shave despite new blades
📋 Technical specifications
| attribute | value |
|---|---|
| Manufacturer's SKU | 422203624371 |
| brand | Philips Norelco |
| Product type | Lower shaving unit – rotation mechanism |
| Number of rotation painters | 3 (for the three shaving heads) |
| Matching to series | Series 9, Series 8, Series 7, Series 6 |
| Part type | Original OEM |
| Including blades | No – mechanism only |
✅ Compatible models
This unit fits the following Philips Norelco models:
Series 9: S9011, S9021, S9031, S9041, S9111, S9121, S9151, S9161, S9171, S9311, S9321, S9371, S9511, S9521, S9522, S9531, S9711, S9721, S9731, S9733, S9751, S9821, S9911, S9988
Series 8: S8880, S8950
Series 7: S7310, S7370, S7371, S7710, S7720, S7730, S7740
Series 6: S6810, S6820, S6850, S6880
⚠️ Important: Before ordering, verify the model number listed on the back of your shaver handle.
🔧 How do you replace the lower shaving unit?
Difficulty level: Simple DIY – up to 5 minutes, no tools required. Replacement is done with just a click and pull.
Replacement steps:
- Turn off the shaver before replacing.
- Pull the shaving head holder upwards from the shaver.
- Remove the old shaving unit (lower mechanism)
- Insert the new unit (422203624371) into place until you hear a click.
- Reattach the head holder.
- Turn on the machine – the heads should rotate quietly and evenly.
💡 Tip from the experts
The common mistake we see: Many customers purchase new blades (SH90) when the machine is making noise – but the blades are not the cause of the noise. The mechanical mechanism that turns them is the cause. In our experience, if the noise is coming from the head area and not the handle, it is almost always the lower unit. Replacing the blades in this situation will not solve the problem.
Another tip: After replacing, apply a small drop of oil to each of the three rotary bearings. This simple action will extend the life of the new unit and reduce noise.
❓ Frequently Asked Questions
What is the difference between the lower shaving unit and the shaving heads (SH90)?
Two completely different parts. The lower shaving unit (422203624371) is the mechanical mechanism – the rotating shafts that move the heads. The shaving heads (SH90) are the blades themselves that come into contact with the skin. If the machine is noisy or the heads rotate heavily – the lower unit. If the shave is less close after a year – the blades (SH90).
Is the lower unit also suitable for the 8 series?
Yes. Unit 422203624371 also fits Series 8 models such as S8880 and S8950, as well as Series 7 and 6. Make sure your model number is listed in the compatible models list before ordering.
Can non-original parts be used instead?
Not recommended. The rotation mechanism is a part with tight measurement tolerances - any slight misalignment in the rotation axis can create increased vibration and accelerate wear of the motor. A non-genuine part can also damage the motor itself in the long run. The original part 422203624371 is guaranteed to fit exactly according to Philips specifications.







